Rooster Built x4
I'm running WinterBrew's kit on my 154, and LOVE it! I had the same reservations as you, confused as to who's clutch kit to buy. Although I am entirely happy with the kit on my sled, I think that you will be fine buying a kit from just about any of the guys on SW who offer them - Turbo Al, WinterBrew, Big John, Dynamo Joe, etc... I really do not think that you will find the "best" kit with from just one supplier. There are just too many variables dependant on the sled, usage, rider, snow conditions, etc. Personally, I would pick a kit from a supplier that is close to your geographical location, or at the very least tests in similar riding conditions that you ride in. Not sure if I would buy a kit from the mid-west if you ride in northern BC for example. I would find out what clutching other riders are using in your area, and then make an educated decision based on thier experience.
Expect to pay $300-350 for a complete kit.